Raver will play genius special agent Paris in the CBS drama, according to TVLine.
The series - which follows a team of crime-busting agents who both work and live together - will be launched via a 'backdoor pilot' aired as an episode of NCIS: LA later this season.
NCIS: LA is itself a spinoff from NCIS, which in turn emerged from the long-running drama JAG.
Other recent cast additions on the as-yet-untitled spinoff include Sex and the City's John Corbett, ER's Scott Grimes and Cougar Town's Edwin Hodge.
Raver's past credits include stints on 24 and Grey's Anatomy - she currently plays a recurring role on NBC sci-fi drama Revolution.
> NCIS: LA to launch own spinoff series
Watch a clip from NCIS: LA below: